I am looking to dynamically change my screen size for a panel. I need more functionality than just 80 x 24. I have tried the terminal command with SCRSIZE and LINESIZE, but they do not change to a wider screen. Any suggestions?

This is generally handled through the 3270 emulator you run on your PC, but the mainframe also has to be set up for the screen size you want to run. Your best bet is to contact your site support group about how to change the screen size in your emulator and get a matched screen size on the mainframe.

Sigh. The first reference in the Google search I cited has a title of "Creating dynamic 3270 screen size definitions for increased productivity". Perhaps if you read that you could find out some of the data that you must change before you can change the screen size within REXX. Probably not, since you seem quite convinced someone on this forum will give the answer you want, but perhaps....

Can you be more clear about what you see now? What size is your emulator configured to now and what are you seeing displayed? How wide of a screen do you see when you use SDSF?

I think you need some things:
1. configure emulator
2. set ISPF setttings to allow greater than 80 width
3. panels need to be written for greater than 80 width
4. application needs to be written to present greater than 80 data

I am building a CICS BMS screen painter (not a fan of SDF2), and I want the option to be able to modify MOD2 and MOD5 maps. I have an assembler utility that displays terminal settings and when invoked, it will jump to 27x132. My goal is to have my screen painter (written in Rexx) to call an assembler program and change the screen size automatically if you are modifying a MOD5 screen.

I can manually switch my terminal screen format to MAX and the screen painter works perfectly, but I do not want the user to manually change their screen format when they need to modify a map.

I also do not want the user to have to page left, right, down, or up to modify a MOD5 map.

it does work - its been done for years. When you say 'that does not work' you need to be more specific. What did you try? How did you determine the screen size and therefore which panel to display? What was the screen size you were displaying and what was the panel expecting it to be?

I know my logical screen is larger than my physical screen. That is what I am trying to programmatically change. I do not want to require the user change their ISPF screen settings manually just to use my editor. I am trying to figure out how I can change that on the fly.

Just to clear things up, changing the screen size in option 0 (Settings) is not a problem. That is not the issue here, it never was...

you can't change physical screen sizes. Emulators are emulating real hardware and the real 3270 terminals could not change screen sizes either (well, they have primary and alternate sizes like a Mod5, but you can't make a mod 2,3, or 4, display more than 80 columns. That is why I suggested that you query the screen size (zwidth?, I forget) and display a panel written for the right size or use expand to widen th area to the right size. But telling an 80 byte physical or emulated terminal that you want to display 132 characters will not work.

I think you need some things:
1. configure emulator
2. logon with VTAM definitions for right terminal definition.
3. set ISPF setttings to allow greater than 80 width
4. panels need to be written for greater than 80 width
5. application needs to be written to present greater than 80 data

Can you verify that another application will display a wide screen? I suggested SDSF

Easy answer (untested):
1. exit ISPF
2. rename your ISPF profile member: ISRPROF, say to OLDPROF
3. restart ISPF - it will make a new ISRPROF member
4. make copy of new ISRPROF, say to 'TEMPPROF'
5. use option 0 to change your 'screen format' to MAX.
6. compare current ISRPROF to TEMPPROF and see which variable changed.
7. That is the variable you need to set from your program
8. restore your original ISRPROF member from OLDPROF

NOTE: you need to add logic to restore the users actual preference when your application is done. And I am pretty sure it will be active for split screen applications.

Screen format
Specification of screen format applies only to 327x and 3290 terminals (or a terminal emulator set to a mode that emulates a 327x or 3290 terminal). ISPF ignores screen format for other types of terminal.

Data
Format is based on data width.

so it should be possible to automatically switch to a 132 display
( that' s what sdsf does automatically )
tested and working on a model 5 to see all the listing without side scrolling

but in split screen editing in the other screen looks weird

the logon mode table must be defined for a model 5 3270
and the emulator must be configured to emulate a model 5

Easy answer (untested):
1. exit ISPF
2. rename your ISPF profile member: ISRPROF, say to OLDPROF
3. restart ISPF - it will make a new ISRPROF member
4. make copy of new ISRPROF, say to 'TEMPPROF'
5. use option 0 to change your 'screen format' to MAX.
6. compare current ISRPROF to TEMPPROF and see which variable changed.
7. That is the variable you need to set from your program
8. restore your original ISRPROF member from OLDPROF

NOTE: you need to add logic to restore the users actual preference when your application is done. And I am pretty sure it will be active for split screen applications.

After doing this, I did a SUPERC comparison on the ISPSPROF member (this is the only one that I can find that has any changes). This is the result:

Screen format
Specification of screen format applies only to 327x and 3290 terminals (or a terminal emulator set to a mode that emulates a 327x or 3290 terminal). ISPF ignores screen format for other types of terminal.

Data
Format is based on data width.

so it should be possible to automatically switch to a 132 display
( that' s what sdsf does automatically )
tested and working on a model 5 to see all the listing without side scrolling

but in split screen editing in the other screen looks weird

the logon mode table must be defined for a model 5 3270
and the emulator must be configured to emulate a model 5

Exactly! The emulator doesn't solely control this. The emulator will prevent you from viewing Mod5 if you do not set it correctly, but ISPF also plays a role.